Possible rebuild of an S54 in an E86 Z4M Coupe

[digger]

If you look at tearing down and rebuilding an engine as a difficult, arduous task then I can see why you might say that but for me it is great fun. I like knowing every component is in the best possible condition. I've torn the car down to the last bolt at the moment while I refinish every surface, replace every bushing, bearing, gasket and seal.
The car was in excellent condition but considering its age and mileage it is a perfect time to refresh everything while parts are still available.

By that explanation why do “half” a job then? Wouldn’t you do the whole shooting match

[Icecream]

If you look at tearing down and rebuilding an engine as a difficult, arduous task then I can see why you might say that but for me it is great fun. I like knowing every component is in the best possible condition. I've torn the car down to the last bolt at the moment while I refinish every surface, replace every bushing, bearing, gasket and seal.
The car was in excellent condition but considering its age and mileage it is a perfect time to refresh everything while parts are still available.

I agree, it actually is great fun but I think what takes away from it is down time and cost for most people. At 90k miles I probably would not have done it myself just because my 200k mile motor was in such amazing condition when I disassembled it (minus the rod bearing) and still didn't burn any oil. If I caught the rod bearing in time there is zero doubt it would have made it to 300K. Check out these WPC pistons from that motor below, crowns, ring lands were perfect and zero pitting. Before getting them WPC treated, they still had most of the factory graphite coating on the skirts.

[grannyknot]

By that explanation why do “half” a job then? Wouldn’t you do the whole shooting match

I have done 95% of the whole shooting match, the other 5%, the rings and cylinder walls don't need restoring.
A dry compression test showed 185 psi on # 1, 2, 4, 5, 6, Vehicle Discussion showed 190 psi. It would be silly to mess with numbers like that and a waste of money.
I can't understand the "drive it until it breaks" mentality, so if you can't understand why someone would restore a car then nothing else I say is going to help.

[digger]

I have done 95% of the whole shooting match, the other 5%, the rings and cylinder walls don't need restoring.
A dry compression test showed 185 psi on # 1, 2, 4, 5, 6, Vehicle Discussion showed 190 psi. It would be silly to mess with numbers like that and a waste of money.
I can't understand the "drive it until it breaks" mentality, so if you can't understand why someone would restore a car then nothing else I say is going to help.

who said drive it until it breaks? I also agree that it doesn't need the rings done i just think it is ironic that you say "I like knowing every component is in the best possible condition. I've torn the car down to the last bolt at the moment while I refinish every surface, replace every bushing, bearing, gasket and seal."
If it was me going that far I'd have been getting some custom Mahle MS slugs with modern rings a small overbore, massage to the CR, perhaps deeper pockets and future proofing it and improving things while i was at it.

[grannyknot]

who said drive it until it breaks? I also agree that it doesn't need the rings done i just think it is ironic that you say "I like knowing every component is in the best possible condition. I've torn the car down to the last bolt at the moment while I refinish every surface, replace every bushing, bearing, gasket and seal."
If it was me going that far I'd have been getting some custom Mahle MS slugs with modern rings a small overbore, massage to the CR, perhaps deeper pockets and future proofing it and improving things while i was at it.

What's ironic? Everything will be in the best possible condition, installing new rings doesn't guarantee you better numbers, I've seen rebuilt engines that had more erratic compression numbers after the work than they had before the rebuild.
Once the engine heads off to the machine shop I loose all control, I don't have the right equipment or expertise so what I get back from them can only be tested once it is fully assembled and running.
Then if I'm not happy with their work I either have to put up with it or forget using the car for the rest of the driving season.
In this situation, having such good compression numbers not only saves me a bundle of money but I remain in control.
I too would love to have stronger, light weight pistons and an overbore, if you are willing to finance that extra work I would be more than happy to take you up on the offer
Unfortunately, I'm already at twice my original budget for this refresh and it keeps creeping up every week, when the car is done next spring I'll have all the basics covered with a few frills added. I'll just have to wait for some more money to appear before I start adding the goodies.

[digger]

What's ironic? Everything will be in the best possible condition, installing new rings doesn't guarantee you better numbers, I've seen rebuilt engines that had more erratic compression numbers after the work than they had before the rebuild.
Once the engine heads off to the machine shop I loose all control, I don't have the right equipment or expertise so what I get back from them can only be tested once it is fully assembled and running.
Then if I'm not happy with their work I either have to put up with it or forget using the car for the rest of the driving season.
In this situation, having such good compression numbers not only saves me a bundle of money but I remain in control.
I too would love to have stronger, light weight pistons and an overbore, if you are willing to finance that extra work I would be more than happy to take you up on the offer
Unfortunately, I'm already at twice my original budget for this refresh and it keeps creeping up every week, when the car is done next spring I'll have all the basics covered with a few frills added. I'll just have to wait for some more money to appear before I start adding the goodies.

that the best part of 100,000 miles somehow equates to "best possible condition" and that a single compression test is the be all of health.

at the other end of the spectrum for anyone on a budget my advice is to address what needs to be addressed for example there is zero need to even do the mains without appropriate evidence

[tlow98]

that the best part of 100,000 miles somehow equates to "best possible condition" and that a single compression test is the be all of health.

at the other end of the spectrum for anyone on a budget my advice is to address what needs to be addressed for example there is zero need to even do the mains without appropriate evidence

Well, sure, but where’s the fun in that? Clearly the guy isn’t sweating a rebuild. He’s in another universe from you and I.

im doing it because I want to, but really mostly bc I have to do it. Le sigh. This BD energy is total inspiration tho.

[grannyknot]

that the best part of 100,000 miles somehow equates to "best possible condition" and that a single compression test is the be all of health.

at the other end of the spectrum for anyone on a budget my advice is to address what needs to be addressed for example there is zero need to even do the mains without appropriate evidence

Oh for God's sake man, now you're really reaching. Your whole argument is this, I'm not playing with my toy the way you would like me to play with my toy and you're trying to convince us that your way is better, that's it.
To me, these are play things and nothing more, just trying having a bit fun in my spare time. You want my used mains so they won't go to waste? They're yours, I'll ship them free of charge.
Good luck to you.

[digger]

Well, sure, but where’s the fun in that? Clearly the guy isn’t sweating a rebuild. He’s in another universe from you and I.

im doing it because I want to, but really mostly bc I have to do it. Le sigh. This BD energy is total inspiration tho.

I rebuild things purely for fun. design custom engine components, make up projects for the sake of it, go whole hog as much as the next person. I also do many things based on condition/ evidence